In recent years, airbags of different types have been developed to protect an occupant from various traffic accidents, in particular car accidents, and rapidly come into practical use as their effectiveness is recognized. Since the airbags are used under any circumstance, they are required to have stable mechanical performance even in severe environments like high temperature and low temperature.
Conventionally, the airbags have been manufactured in the following manner. A plain weave fabric made of 334 to 1,112 dtex nylon 6,6 or nylon 6 filament yarns is coated with an elastomer of, for example, a synthetic rubber, such as chloroprene, chlorosulfonated olefin, or silicone to improve the heat resistance, the flame resistance, and the air-barrier property of the fabric. Then, the resulting laminated base fabric is cut and sewed into a bag.
When a filament fabric is coated with, for example, a chloroprene elastomer to manufacture a base fabric, 90 to 120 g/m2 of the chloroprene elastomer must be applied to the filament fabric to improve the heat resistance and the flame resistance of the base fabric. However, this undesirably increases the thickness and the packed volume of the base fabric, resulting in poor mountability of the base fabric. When a silicone elastomer, which has higher heat resistance and higher cold resistance than the chloroprene elastomer, was used, the coating weight was reduced to 40 to 60 g/m2. Thus, the mountability and compactness was improved significantly, but it was still not satisfying. The bag thus manufactured had another problem in that the bag was hard to fold into a package when the bag was folded and mounted.
Thus, a base fabric coated with a smaller amount of silicone has recently been studied to solve such problems. For example, an airbag characterized in that an elastomer 3.0 times or more as thick as weaving yarns constituting the fabric is predominantly applied to the mesh of the fabric is proposed (see, for example, Japanese Patent No. 2853936). Although this airbag has improved mountability and compactness, the adhesion between the resin film and the fabric is not satisfying. Another proposition is a method for manufacturing an airbag fabric, characterized in that woven filaments are impregnated with an aqueous silicone resin emulsion such that the deposit of the silicone resin ranges from 0.1 g/m2 to 10 g/m2 (see, for example, Japanese Patent No. 3206758). While this method improves the adhesion between the resin film and the fabric to some extent, the air-barrier property or the mountability and compactness are not satisfactory.